'Harry attends a few lessons, gets up to a bit of mischief, hears rumours of war in the North and generally awaits the arrival in the plot of Sirius Black'

With Chris Columbus out of the reckoning for the third Harry Potter film, Harry Potter And The Prisoner Of Azkaban, it seems a bit of an oddity that the production team decided to turn to Mexican Alfonso Cuarón. Cuarón was, at this stage in his career, still several years off from making masterpiece dystopia, Children Of Men and had here just come off the back of making Y Tu Mamá También, a film the US censor rated R only after cuts, still warning that it had, 'strong sexual content involving teens, drug use and language'. Not exactly your prototypical candidate for a Harry Potter film then.

Widely regarded as the 'darkest' of the franchise (although its successor, Goblet Of Fire, gives it a run for its money) Azkaban is notable for the directing decisions you just can't imagine a Columbus or a David Yates making. In what other film in the franchise, for example, can you imagine a director planting a cameoing Ian Brown (yes, that Ian Brown, formerly of The Stone Roses), casually reading a Steven Hawkins book in the bar of a magical pub? The opening scenes; from Aunt Marge (Pam Ferris) floating away, to the playground that moves by itself, to the decidedly acid-trippy bus ride, are a delight of bizarre directorial tricks and visual playthings.

Although this toying with the look of Potter carries on throughout, the film suffers notably on two fronts. The first is the saggy section occupying the first hour or so of Harry's (Daniel Radcliffe) re-arrival at Hogwarts. He attends a few lessons, gets up to a bit of mischief, hears rumours of war in the North and generally awaits the arrival in the plot of Sirius Black. It's a lot of nothing really, and the plot really struggles to find a handhold.

The other troublesome problem is the quandary Cuarón gets himself into with all the malevolence he spends so much time crafting. This being a franchise, PG-rated film and all, he never gets to score a payoff. There's no realisation of the terrible deeds he seems to want to pursue. Azkaban is, it has to be said, probably the wrong film to pair up with a director willing to push the envelope towards the dark side. Had the producers given him Goblet Of Fire to play with, a film with real tragedy at its core, the results could have been truly startling. As it is, Azkaban feels like a whispered ghost tale of little substance.

Not that the whole thing falls down completely around the Mexican's ears. Once the narrative drive is established beyond the fact that Harry has to go to a few classes occasionally, the entire jaunt perks. The finale perhaps suffers from not-enough-evil, too little Lord Voldemort, but still, there's threat here and a satisfactory conclusion to a somewhat convoluted story.

The risk of hiring Cuarón brings dangers and rewards in equal measure and although Azkaban may not be the best Potter, it at least marks itself out as being a notable one and a fine recovery from the aimless, harmless, plodding of Chamber Of Secrets.